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Fair Value Measurements - Quantitative Information for Level 3 Measurements (Details) - Recurring Fair Value Measurements $ in Millions | Dec. 31, 2024 USD ($) | Dec. 31, 2023 USD ($)
--- | --- | ---
Unobservable inputs |  |
Assets measured at fair value | $ 249,740.8 | $ 240,637.6
Liabilities measured at fair value | 1,840.8 | 1,823.4
Fair value hierarchy Level 3 |  |
Unobservable inputs |  |
Assets measured at fair value | 5,680.2 | 5,130.2
Liabilities measured at fair value | 2,366.1 | 2,317.6
Fair value hierarchy Level 3 | Investment and universal life contracts |  |
Unobservable inputs |  |
Liabilities measured at fair value | $ (578.4) | $ (115.5)
Embedded derivative, Valuation technique | Discounted cash flow | Discounted cash flow
Fair value hierarchy Level 3 | Investment and universal life contracts | Discounted cash flow | Long duration interest rate | Minimum |  |
Unobservable inputs |  |
Embedded derivative, Input | 0.03 | 0.025
Fair value hierarchy Level 3 | Investment and universal life contracts | Discounted cash flow | Long duration interest rate | Maximum |  |
Unobservable inputs |  |
Embedded derivative, Input | 0.049 | 0.048
Fair value hierarchy Level 3 | Investment and universal life contracts | Discounted cash flow | Long duration interest rate | Weighted average input |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input |  | 0.04
Embedded derivative, Input | 0.048 |
Fair value hierarchy Level 3 | Investment and universal life contracts | Discounted cash flow | Long-term equity market volatility | Minimum |  |
Unobservable inputs |  |
Embedded derivative, Input | 0.145 | 0.155
Fair value hierarchy Level 3 | Investment and universal life contracts | Discounted cash flow | Long-term equity market volatility | Maximum |  |
Unobservable inputs |  |
Embedded derivative, Input | 0.493 | 0.401
Fair value hierarchy Level 3 | Investment and universal life contracts | Discounted cash flow | Long-term equity market volatility | Weighted average input |  |
Unobservable inputs |  |
Embedded derivative, Input | 0.214 | 0.192
Fair value hierarchy Level 3 | Investment and universal life contracts | Discounted cash flow | Non-performance risk | Minimum |  |
Unobservable inputs |  |
Embedded derivative, Input | 0.004 | 0.008
Fair value hierarchy Level 3 | Investment and universal life contracts | Discounted cash flow | Non-performance risk | Maximum |  |
Unobservable inputs |  |
Embedded derivative, Input | 0.011 | 0.016
Fair value hierarchy Level 3 | Investment and universal life contracts | Discounted cash flow | Non-performance risk | Weighted average input |  |
Unobservable inputs |  |
Embedded derivative, Input | 0.008 | 0.011
Fair value hierarchy Level 3 | Investment and universal life contracts | Discounted cash flow | Lapse rate | Minimum |  |
Unobservable inputs |  |
Embedded derivative, Input | 0 | 0
Fair value hierarchy Level 3 | Investment and universal life contracts | Discounted cash flow | Lapse rate | Maximum |  |
Unobservable inputs |  |
Embedded derivative, Input | 0.55 | 0.55
Fair value hierarchy Level 3 | Investment and universal life contracts | Discounted cash flow | Lapse rate | Weighted average input |  |
Unobservable inputs |  |
Embedded derivative, Input | 0.085 | 0.07
Fair value hierarchy Level 3 | Fixed maturities | Trading |  |
Unobservable inputs |  |
Assets measured at fair value | $ 289.6 | $ 203.9
Fair value hierarchy Level 3 | Fixed maturities | Trading | Discounted cash flow | Discount rate | Minimum |  |
Unobservable inputs |  |
Fixed maturities, trading, Input | 0.095 | 0.114
Fair value hierarchy Level 3 | Fixed maturities | Trading | Discounted cash flow | Discount rate | Maximum |  |
Unobservable inputs |  |
Fixed maturities, trading, Input | 0.13 | 0.223
Fair value hierarchy Level 3 | Fixed maturities | Trading | Discounted cash flow | Discount rate | Weighted average input |  |
Unobservable inputs |  |
Fixed maturities, trading, Input | 0.099 | 0.133
Fair value hierarchy Level 3 | Fixed maturities | Trading | Discounted cash flow | Earnings before interest, taxes, depreciation and amortization multiple |  |
Unobservable inputs |  |
Fixed maturities, trading, Input | 1.1 |
Fair value hierarchy Level 3 | Fixed maturities | Trading | Discounted cash flow | Earnings before interest, taxes, depreciation and amortization multiple | Weighted average input |  |
Unobservable inputs |  |
Fixed maturities, trading, Input | 1.1 |
Fair value hierarchy Level 3 | Fixed maturities | Trading | Discounted cash flow | Comparability adjustment | Minimum |  |
Unobservable inputs |  |
Fixed maturities, trading, Input | (0.0032) |
Fair value hierarchy Level 3 | Fixed maturities | Trading | Discounted cash flow | Comparability adjustment | Maximum |  |
Unobservable inputs |  |
Fixed maturities, trading, Input | 0.2947 |
Fair value hierarchy Level 3 | Fixed maturities | Trading | Discounted cash flow | Comparability adjustment | Weighted average input |  |
Unobservable inputs |  |
Fixed maturities, trading, Input | 0.0152 |
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale |  |
Unobservable inputs |  |
Assets measured at fair value | $ 1,817.8 | $ 1,997.4
Fixed maturities, available-for-sale, Valuation technique | Discounted cash flow | Discounted cash flow
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Discount rate | Minimum |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.021 | 0.049
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Discount rate | Maximum |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.127 | 0.242
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Discount rate | Weighted average input |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.08 | 0.12
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Earnings before interest, taxes, depreciation and amortization multiple |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input |  | 3.25
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Earnings before interest, taxes, depreciation and amortization multiple | Minimum |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 1.1 |
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Earnings before interest, taxes, depreciation and amortization multiple | Maximum |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 1.7 |
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Earnings before interest, taxes, depreciation and amortization multiple | Weighted average input |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 1.3 | 3.25
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Illiquidity premium | Minimum |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.0030 | 0.0030
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Illiquidity premium | Maximum |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.0791 | 0.0483
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Illiquidity premium | Weighted average input |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.0142 | 0.0121
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Comparability adjustment | Minimum |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | (0.0042) | 0.0067
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Comparability adjustment | Maximum |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.2947 | 0.0217
Fair value hierarchy Level 3 | Corporate debt securities | Available-for-sale | Discounted cash flow | Comparability adjustment | Weighted average input |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.0149 | 0.0141
Fair value hierarchy Level 3 | Collateralized debt obligations | Available-for-sale |  |
Unobservable inputs |  |
Assets measured at fair value |  | $ 74.6
Fixed maturities, available-for-sale, Valuation technique |  | Discounted cash flow
Fair value hierarchy Level 3 | Collateralized debt obligations | Available-for-sale | Discounted cash flow | Discount rate |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input |  | 0.041
Fair value hierarchy Level 3 | Collateralized debt obligations | Available-for-sale | Discounted cash flow | Discount rate | Weighted average input |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input |  | 0.041
Fair value hierarchy Level 3 | Collateralized debt obligations | Available-for-sale | Discounted cash flow | Comparability adjustment |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input |  | 0.0020
Fair value hierarchy Level 3 | Collateralized debt obligations | Available-for-sale | Discounted cash flow | Comparability adjustment | Weighted average input |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input |  | 0.0020
Fair value hierarchy Level 3 | Other debt obligations | Available-for-sale |  |
Unobservable inputs |  |
Assets measured at fair value | $ 1,343.1 | $ 879.5
Fixed maturities, available-for-sale, Valuation technique | Discounted cash flow | Discounted cash flow
Fair value hierarchy Level 3 | Other debt obligations | Available-for-sale | Discounted cash flow | Discount rate | Minimum |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.049 | 0.05
Fair value hierarchy Level 3 | Other debt obligations | Available-for-sale | Discounted cash flow | Discount rate | Maximum |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.077 | 0.106
Fair value hierarchy Level 3 | Other debt obligations | Available-for-sale | Discounted cash flow | Discount rate | Weighted average input |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.054 | 0.074
Fair value hierarchy Level 3 | Other debt obligations | Available-for-sale | Discounted cash flow | Illiquidity premium | Minimum |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | (0.0083) | 0.0069
Fair value hierarchy Level 3 | Other debt obligations | Available-for-sale | Discounted cash flow | Illiquidity premium | Maximum |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.0260 | 0.0650
Fair value hierarchy Level 3 | Other debt obligations | Available-for-sale | Discounted cash flow | Illiquidity premium | Weighted average input |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.0120 | 0.0337
Fair value hierarchy Level 3 | Other debt obligations | Available-for-sale | Discounted cash flow | Comparability adjustment | Minimum |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | (0.0019) | (0.0020)
Fair value hierarchy Level 3 | Other debt obligations | Available-for-sale | Discounted cash flow | Comparability adjustment | Maximum |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.0415 | 0.0213
Fair value hierarchy Level 3 | Other debt obligations | Available-for-sale | Discounted cash flow | Comparability adjustment | Weighted average input |  |
Unobservable inputs |  |
Fixed maturities, available-for-sale, Input | 0.0128 | 0.0092
Fair value hierarchy Level 3 | Other investments |  |
Unobservable inputs |  |
Assets measured at fair value | $ 129.0 | $ 163.2
Fair value hierarchy Level 3 | Other investments | Discounted cash flow | Discount rate | Minimum |  |
Unobservable inputs |  |
Other investments, Input | 0.115 | 0.12
Fair value hierarchy Level 3 | Other investments | Discounted cash flow | Discount rate | Maximum |  |
Unobservable inputs |  |
Other investments, Input | 0.135 | 0.135
Fair value hierarchy Level 3 | Other investments | Discounted cash flow | Discount rate | Weighted average input |  |
Unobservable inputs |  |
Other investments, Input | 0.124 |
Separate account assets, Input |  | 0.126
Fair value hierarchy Level 3 | Other investments | Discounted cash flow | Probability of default | Minimum |  |
Unobservable inputs |  |
Other investments, Input | 0.06 | 0.06
Fair value hierarchy Level 3 | Other investments | Discounted cash flow | Probability of default | Maximum |  |
Unobservable inputs |  |
Other investments, Input | 0.10 | 0.10
Fair value hierarchy Level 3 | Other investments | Discounted cash flow | Probability of default | Weighted average input |  |
Unobservable inputs |  |
Other investments, Input | 0.081 | 0.085
Fair value hierarchy Level 3 | Other investments | Discounted cash flow | Potential loss severity | Minimum |  |
Unobservable inputs |  |
Other investments, Input | 0.87 | 0.87
Fair value hierarchy Level 3 | Other investments | Discounted cash flow | Potential loss severity | Maximum |  |
Unobservable inputs |  |
Other investments, Input | 1 | 1
Fair value hierarchy Level 3 | Other investments | Discounted cash flow | Potential loss severity | Weighted average input |  |
Unobservable inputs |  |
Other investments, Input | 0.92 | 0.907
Fair value hierarchy Level 3 | Separate account assets |  |
Unobservable inputs |  |
Assets measured at fair value | $ 726.7 | $ 752.8
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate | Discount rate | Minimum |  |
Unobservable inputs |  |
Separate account assets, Input | 0.07 | 0.065
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate | Discount rate | Maximum |  |
Unobservable inputs |  |
Separate account assets, Input | 0.11 | 0.10
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate | Discount rate | Weighted average input |  |
Unobservable inputs |  |
Separate account assets, Input | 0.072 | 0.075
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate | Terminal capitalization rate | Minimum |  |
Unobservable inputs |  |
Separate account assets, Input | 0.055 | 0.053
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate | Terminal capitalization rate | Maximum |  |
Unobservable inputs |  |
Separate account assets, Input | 0.095 | 0.095
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate | Terminal capitalization rate | Weighted average input |  |
Unobservable inputs |  |
Separate account assets, Input | 0.06 | 0.061
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate | Average market rent growth rate | Minimum |  |
Unobservable inputs |  |
Separate account assets, Input | 0.02 | 0.02
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate | Average market rent growth rate | Maximum |  |
Unobservable inputs |  |
Separate account assets, Input | 0.045 | 0.037
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate | Average market rent growth rate | Weighted average input |  |
Unobservable inputs |  |
Separate account assets, Input | 0.027 | 0.029
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate debt | Loan to value | Minimum |  |
Unobservable inputs |  |
Separate account assets, Input | 0.464 | 0.46
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate debt | Loan to value | Maximum |  |
Unobservable inputs |  |
Separate account assets, Input | 0.695 | 0.72
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate debt | Loan to value | Weighted average input |  |
Unobservable inputs |  |
Separate account assets, Input | 0.592 | 0.553
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate debt | Market interest rate | Minimum |  |
Unobservable inputs |  |
Separate account assets, Input | 0.049 | 0.053
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate debt | Market interest rate | Maximum |  |
Unobservable inputs |  |
Separate account assets, Input | 0.072 | 0.081
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate debt | Market interest rate | Weighted average input |  |
Unobservable inputs |  |
Separate account assets, Input | 0.061 | 0.064

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